Most countries place their orders about 9-12 months in advance based on national health policies so have already decided on their doses for this year's flu season.
The Geneva-based WHO also insisted it would never endorse a vaccine that has not proven safe and effective, amid concerns over the rush to develop a jab for Covid-19.
The UN health agency welcomed the fact that a "considerable number" of vaccine candidates had entered final stage Phase III trials, which typically involve tens of thousands of people.
The global vaccine allocation plan, called COVAX, aims to help buy and fairly distribute deliver 2 billion doses of approved vaccines by the end of 2021.
We are seeing an epidemiological curve that is either stabilising or decreasing, representing a sign of hope.
Since COVID-19 cases were first identified in December last year, the virus is thought to have killed nearly 850,000 people, the latest Reuters tally showed.
With both figures expected to be reached within days, the WHO stressed it was never too late to take action to suppress the COVID-19 crisis that has gripped the planet.
China -- excluding Hong Kong and Macau -- has to date declared 84,491 cases (27 new since Tuesday), including 4,634 deaths (0 new), and 79,047 recoveries.
"People are still thinking about seasons. What we all need to get our heads around is this is a new virus and...this one is behaving differently," Margaret Harris told a virtual briefing in Geneva.
The number of infections in Europe crossed three million on Thursday, a fifth of the world's more than 15 million cases. It remains the hardest hit in terms of deaths, with 206,633 out of 627,307 worldwide.
With new infections spreading like wildfire, many countries were reimposing restrictions on Monday, locking down towns and cities and reintroducing measures to halt the spread of the sickness.
The pandemic, which has hit hard in nations with widespread poverty, could cause another 83 to 132 million people to become undernourished this year, the report says.
"The number of cases reported in June alone is higher than the total number of cases reported during the four months following the first reported case in the Region on 29 January," he said.
Spain suffered a particularly deadly outbreak of the virus which infected more than 244,000 people, with its figure of 27,136 dead making it the sixth worst-hit country in the world.
South America has been badly hit by COVID-19, with the World Health Organization warning earlier this month that medical facilities across the continent are at risk of being overwhelmed.
Speaking in a virtual briefing from Washington-based Pan American Health Organization, Etienne said Brazil accounts for 23pc of the more than 3.8 million cases in the Americas and 23pc.
Abe, speaking to parliament, said it was important to share information and knowledge from each nation, including Taiwan, on an infectious disease that has had significant impact globally.
